a 50kg skater on level ice, has built up her speed to 30km/h. how far will she coast before sliding friction dissipates her energy?​

Answer:

Option b, cosine.

Explanation:

Below you can see an image that illustrates this situation.

Remember that for a triangle rectangle with a given angle θ, we have:

Cos(θ) = (adjacent cathetus)/(hypotenuse)

In the image, you can see a vector of magnitude M, and the angle θ defined between the vector and the positive y-axis.

In this case, the y-component is the adjacent cathetus and the hypotenuse is the magnitude of the vector.

Then we will have:

Cos(θ) = (adjacent cathetus)/(hypotenuse) = y/M

solving that for y, we get:

y = Cos(θ)*M

Then the y-component is the vector's magnitude multiplied by the cosine of the angle between the vector and the y-axis.

The correct option is b.

Answer:

(b) cosine

Explanation:

In a 2-dimensional Cartesian coordinate system, a vector has a x-component and/or a y-component. To get these components, the magnitude of the vector is resolved with respect to the x-axis and the y-axis by multiplying it (the magnitude) by some trigonometric function with respect to the angle between the vector and the x or y axis.

For example, given a vector A of magnitude A which makes an angle α with the x-axis and an angle β with the y-axis, the x and y components of the vector A can be found as follows;

i. x-component is given by [tex]A_{x}[/tex]

[tex]A_{x}[/tex] = A cos α (with respect to the angle between A and the x-axis)  or

[tex]A_{x}[/tex] = A sin β (with respect to the angle between A and the y-axis)

ii. y-component is given by [tex]A_{y}[/tex]

[tex]A_{y}[/tex] = A sin α (with respect to the angle between A and the x-axis)  or

[tex]A_{y}[/tex] = A cos β (with respect to the angle between A and the y-axis)

Therefore, the y-component of a vector in a 2-dimensional Cartesian coordinate is given by the product of the magnitude of the vector and the cosine of the angle between the vector and the y-axis.

Answer: The weight of the object is 29.4 N

Explanation:

To calculate the weight of the object, we use the equation:

[tex]W=m\times g[/tex]

where,

m = mass of the object = 3 kg

g = acceleration due to gravity = [tex]9.8m/s^2[/tex]

Putting values in above equation, we get:

[tex]W=3kg\times 9.8m/s^2\\\\W=29.4N[/tex]

Hence, the weight of the object is 29.4 N

Answer:

29.15 N

Explanation:

Applying,

Pythagoras theorem,

a² = b²+c²................ Equation 1

Where a = resultant of the two forces, b = first force, c = second force.

From the diagram,

Given: b = 15 N, c = 25 N

Substitute these values into equation 1

a² = 15²+25²

a² = 225+625

a² = 850

a = √850

a = 29.15 N

Hence the resultant of the two forces is 29.15 N

We call the acceleration of an object moving in uniform circular motion— resulting from a net external force—the centripetal ...

Answer:

a)   L = 4.75 103 kg m² / s,  b)  K_total = 2.57 10³ J,  

c)   L₀ = L_f =4.75 103 kg m² / s,  d)  K = 1.03 10⁴ J,  K = 1.03 10⁴ J

Explanation:

a) the angular momentum is the sum of the angular momentum of each astronaut

the distance is measured from the center of the circle r = 10/2 = 5.0 m

            L = 2m v r

            L = 2  88.0 5.40 5.0

            L = 4.75 103 kg m² / s

b) rotational kinetic energy

            K = ½ I w²

As there are two astronauts, the total energy is the sum of the energy of each no.

The moment of inertia of a point mass

             I = m r²

             I = 88 5²

             I = 2.2 10³ kg m²

the angular velocity is given by

             v = w r

             w = v / r

             w = 5.40 / 5

             w = 1.08 rad / s

the kinetic energy of the system

             K_total = 2 K

             K_total = 2 (½ I w²)

             K_total = 2.2 10³ 1.08²

             K_total = 2.57 10³ J

c, d) as astronauts are isolated in space, these speeds do not change unless there is an interaction between them, for example they approach each other, suppose they reduce their distance by half

             r = 2.5 m

             I = 88 2.5²

             I = 5.5 10² kg m²

for the change in angular velocity let us use the conservation of moment

            L₀ = L_f

            2Io wo = 2 I w

            w = Io / I wo

            w = 2.2 10³ / 5.5 10² 1.08

            w = 4.32 rad / s

linear velocity is

            v = w r

            v = 4.32 2.5

             K = 1.03 10⁴ J

the kinetic energy of the system is

            K = 5.5 10² 4.32²

            K = 1.03 10⁴ J

Answer:

See annex

Explanation:

By convention potential at ∞    V(∞ ) = 0

As the distance from the sphere decreases the potential increases up to the point d = R  ( R is the radius of the sphere. That potential remains constant while d = R and becomes 0 inside the sphere where there is not free charges and therefore the electric field is 0 and so is the potential.

I am sorry I could not make a better graph

The graph that best  illustrates the potential (relative to infinity) produced by this sphere as a function of the distance r from the center of the sphere is attached as an image below

[tex]V = \frac{KQ}{R}[/tex]

for r <= R

[tex]V = \frac{KQ}{r}[/tex]

for  r > R  

Therefore the graph will be

For more information on potentials as function of distance

https://brainly.com/question/24146175?referrer=searchResults

Answer:

1995 and 2000 , 4 trillions

Explanation:

Answer:

1995 and 2000.4 trillion

Explanation:

Edge 2021

Answer:

Charles law

Explanation:

Charle's law states that the volume (V) of a given gas is directly proportional to the absolute temperature (T) at a constant pressure.

That is;

: V ∝ T

: V/T = K

According to this question, the volume of a balloon is warmed up but the pressure is kept the same. Charles law will be used because it shows the relationship between the volume (V) and the temperature (heat) at a constant pressure (P).

Answer:

The answer is "Option A"

Explanation:

Energy stored in capcitor[tex]=\frac{1}{2}\ cv^2[/tex]

For point A:

[tex]C_A=\frac{\varepsilon_0 2A}{\frac{d}{2}}=\frac{4\ \varepsilon_0 A}{d}\\\\[/tex]

For point B:

[tex]C_B=\frac{\varepsilon_0 2A}{2d}=\frac{\varepsilon_0 A}{d}\\\\[/tex]

For point C:

[tex]C_c=\frac{\varepsilon_0 A}{d}\\\\[/tex]

For point D:

[tex]C_D=\frac{\varepsilon_0 A}{2 \frac{d}{2}}=\frac{\varepsilon_0 A}{d}\\\\[/tex]

For point E:  [tex]C_E=\frac{\varepsilon_0 A}{2 \times 2d}=\frac{\varepsilon_0 A}{4d}\\\\[/tex]

therefore C_A has the maximum capacitance and max energy same energy is dir proportional to C for the same J

Explanation:

No. From your own reference frame, nothing will change. Everything will look the same to you even if you're traveling at 99% speed of light. However, an outside observer will see you shrink to about 14% of your original length along the direction of your motion according to the Lorentz contraction predicted by special relativity:

[tex]L=L_{0} \sqrt{1 - \frac{v^2 }{c^2 }}[/tex]

Answer:

a   c

Explanation:

edu 2021

Answer:

a)  [tex]d=11m[/tex]

b)  [tex]T=4.68s[/tex]

Explanation:

From the question we are told that:

Wavelength [tex]\lambda=22m[/tex]

Velocity [tex]v=4.6m/s[/tex]

a)

Generally the equation for distance between her and the wall d is mathematically given by

Since

The First Anti node distance is [tex]\frac{\lambda}{2}[/tex]

Therefore

 [tex]d= \frac{\22}{2}[/tex]

 [tex]d=11m[/tex]

b)

Generally the equation for her up-and-down motion is mathematically given by

 [tex]T=\frac{22}{4.7}[/tex]

 [tex]T=4.68s[/tex]

Answer:

The correct answer is "4000 J".

Explanation:

Given that,

Force,

= 200 N

Displacement,

= 20 m

Now,

The work done will be:

⇒ [tex]Work=Force\times displacement[/tex]

By putting the values, we get

              [tex]=200\times 20[/tex]

              [tex]=4000 \ J[/tex]

Answer:

122.5 ohm

Explanation:

Given :

P=40 w

V= 70 V

R=?

Resistance can be calculated as :

[tex]P=\frac{V^{2} }{R} \\40=\frac{(70)^{2} }{R}\\40=\frac{4900}{R} \\R=\frac{4900}{40} \\R=122.5 ohm[/tex]

Therefore, resistance of the bulb will be 122.5 ohm

Answer:

Thus, [tex]\frac{1 rev}{min} =\frac{2\pi}{60} rad/s[/tex]

Explanation:

The angular speed is defined as the rate of change of angular velocity.

Its SI unit is rad/s and other units are rev/min or rev/s.

[tex]\frac{1 rev}{min } = \frac{1 rev}{60 sec}\\\\1 rev = 2\pi rad\\\\So\\\\\frac{1 rev}{min} = \frac{2\pi}{60} rad/s[/tex]

Explanation:

kinetic energy was converted to potential energy in the spring.

the answer is in the above image

Answer:

100J

Explanation:

Kinetic energy=1/2mv^2

Kinetic energy=(1/2 x 8)x5^2

Kinetic energy=4x25

Kinetic energy=100

100J

Answer:

T=0,25s

Explanation

5s>20vong  1s>4vong

omega= 8pi

omega=2pi/T

Answer:

power = 4 watt

Explanation:

work done = force * distance

=6*2

=12 joule

power = work done/time taken

=12/3

=4 watt

As the force is exerted across the given distance and time, the power delivered 4Watts.

Power is simply referred to as the quantity of energy transferred per unit time.

It is expressed as;

P = Work done / time elapsed = W / t

Work is simply the measure of energy transfer that takes place when an object is moved over a given distance by a push or pull force.

It is expressed as;

W = Force × distance = F × d

Hence;

Power P = W / t

Power P = (  F × d ) / t

Given the data in the question;

To determine the power delivered, we substitute our given values into the derived equation above.

P = (  F × d ) / t

P = (  6kgm/s² × 2m ) / 3s

P = ( 12kgm²/s² ) / 3s

P = 4kgm²/s³

P = 4Watts

Therefore, as the force is exerted across the given distance and time, the power delivered 4Watts.

Learn more about force here: https://brainly.com/question/15872381

Answer:

48.9 is the answer I think !

Answer:

28.4

Explanation:

Answer:

The surface tension is 190.2 N/m.

Explanation:

Initial radius, r = 4 cm

final radius, r' = 6 cm

Work doen, W = 15 J

Let the surface tension is T.

The work  done is given by

W = Surface Tension x change in surface area

[tex]15 = T \times 4\pi^2(r'^2 - r^2)\\\\15 = T \times 4 \times 3.14\times 3.14 (0.06^2- 0.04^2)\\\\15 = T\times 0.0788\\\\T = 190.2 N/m[/tex]

Answer:

2.86×10⁻¹⁸ seconds

Explanation:

Applying,

P = VI................ Equation 1

Where P = Power, V = Voltage, I = Current.

make I the subject of the equation

I = P/V................ Equation 2

From the question,

Given: P = 0.414 W, V = 1.50 V

Substitute into equation 2

I = 0.414/1.50

I = 0.276 A

Also,

Q = It............... Equation 3

Where Q = amount of charge, t = time

make t the subject of the equation

t = Q/I.................. Equation 4

From the question,

4.931020 electrons has a charge of (4.931020×1.6020×10⁻¹⁹) coulombs

Q = 7.899×10⁻¹⁹ C

Substitute these value into equation 4

t =  7.899×10⁻¹⁹/0.276

t = 2.86×10⁻¹⁸ seconds

Answer:

450N

Explanation:

weight= m*g

weight=45*10

weight=450N

Answer:

B.

Explanation:

HNO2 is less stable thus dissociates easily to HNO3 + NO + H2O while HNO3 is a strong acid. Thus when they react with H2O they form acid rain

Answer:

B

Explanation:

dont have one just trust me

Answer:

The velocity of the particle = -1.92 m/s

The speed of the particle = 5.72 m/s

Explanation:

Given equation of motion;

[tex]f(t) = 18 \ + \ \frac{48}{t} \ + \ 1[/tex]

Velocity is defined as the change in displacement with time.

[tex]V = \frac{df(t)}{dt} = -\frac{48}{t^2} \\\\at \ t = 5 \ s\\\\V = -\frac{48}{5^2} = \frac{-48}{25} = - 1.92 \ m/s[/tex]

The distance traveled by the particle in 5 s:

[tex]s = f(5) = 18 + \frac{48}{5} + 1\\\\s= 28.6 \ m[/tex]

The speed of the particle when t = 5s

[tex]Speed = \frac{28.6}{5} = 5.72 \ m/s[/tex]

Explanation:

acceleration is weight*gravity

tension is the weight In Newtons

Explanation:

the answer is in the above image

Answer:

Flux is 21 Nm^2/C.

Explanation:

Electric field, E = 6 N/C along X axis

Electric filed vector, E = 6 i N/C

Area, A = 4 square meter

Area vector

[tex]\overrightarrow{A} = 4 (cos30 \widehat{i} + sin 30 \widehat{j})\\\\\overrightarrow{A} = 3.5 \widehat{i} + 2 \widehat{j}\\[/tex]

The flux is given by

[tex]\phi= \overrightarrow{E}.\overrightarrow{A}\\\\\phi = 6 \widehat{i} . \left (3.5 \widehat{i} + 2 \widehat{j} \right )\\\\\phi = 21 Nm^2/C[/tex]

Answer:

They investigated Hooke's law.

Explanation:

[tex]{ \tt{force \: \alpha \: extension }} \\ { \boxed{ \bf{F = kx}}} \\ x \: is \: extension \\ F \: is \: force \\ k \: is \: constant : k = 1[/tex]

Explanation:

.....................................

Answer:

1 second is defined as 1/86400th part of a mean solar day.